Bobbin changing apparatus

ABSTRACT

An automatic bobbin changing apparatus for a textile machine includes at least one bobbin gripper. A carrier is provided for the bobbin. Controlled instrumentalities are provided to effect movement of the bobbin gripper. A sensor, preferably in the form of a switch, is operatively arranged to sense the impeding of the bobbin gripper as it moves along a predetermined path. A control circuit responds to the control signal which may be produced by the sensor and produces an output signal. The controlled instrumentalities respond to the output signal and either stop the advance of the bobbin gripper or reverse its direction.

[54] BOBBIN CHANGING APPARATUS [75] Inventors: Giinter Schulz; Wolfgang lgel, both i of Ebersbach, Germany [73] Assignee: Zinser-Textilmaschinen Gmbll,

Ebersbach, Germany [22] Filed: June 27, 1973 [21] Appl. No.: 374,136

[30] Foreign Application Priority Data June 27, 1972 Germany 2231377 [52] U.S. Cl. 57/52 [51] Int. Cl. D01h 9/04 [58] Field of Search 57/52-54, 78, 57/34 [56] References Cited UNITED STATES PATENTS 3,462,934 8/1969 Schulz et al. 57/52 25 r 26 i i l I 15 1 I I III l' I f/ 1 I 2/1974 Kaufmann et al. 57/52 Primary Examiner-John W. l-luckert Assistant Examiner-Charles Gorenstein Attorney, Agent, or Firm-Edwin E. Greigg [57] ABSTRACT An automatic bobbin changing apparatus for a textile machine includes at least one bobbin gripper. A carrier is provided for the bobbin. Controlled instrumentalities are provided to effect movement of the bobbin gripper. A sensor, preferably in the form of a switch, is operatively arranged to sense the impeding of the bobbin gripper as it moves along a predetermined path. A control circuit responds to the control signal which may be produced by the sensor and produces an output signal. The controlled instrumentalities respond to the output signal and either stop the advance of the bobbin gripper or reverse its direction.

24 Claims, 5 Drawing Figures PATENTEDJuL 22 ms SHEET FIGZ BOBBIN CHANGING APPARATUS BACKGROUND OF THE INVENTION This invention relates to an automatic bobbin changing apparatus for a textile machine. The invention relates, more particularly, to an automatic bobbin changing apparatus which includes at least one bobbin gripper, which is adjustable in position by means of a control and drive mechanism; and at least one carrier on which the bobbin gripper or grippers are disposed for gripping and holding bobbins.

The bobbin changing apparatus is particularly useful in conjunction with spinning machines, winding machines, twisting machines and the like.

As used herein, the term bobbin means any type of hollow member, including spools and the like, on which thread or yarn packages are or may be wound on textile machines.

Spinning machines, twisting machines and winding machines are often equipped with automatic bobbin changing apparatuses which automatically exchange full bobbins for empty bobbins. For example, bobbins carrying thread or yarn packages obtained by winding on an associated machine are exchanged for empty bobbins. Such bobbin changing apparatuses may also, in certain cases, be provided on different textile machines, for example, on winding machines and the like. Such bobbin changing apparatus include bobbin grippers for gripping and holding the full and empty bobbins during transport. Bobbin grippers are usually disposed on one or more carriers which are moved in a manner necessary to effect the bobbin changing by means of control and driving devices. There exist known bobbin changing apparatuses which consist of a single bobbin gripper disposed on a carrier. In these cases, the bobbins to be changed are exchanged sequentially. In general, however, a large number of bobbin grippers are disposed on each carrier in order to be able to exchange simultaneously a multitude of bobbins. An automatic bobbin changing apparatus of this type is described, for example, in US. Pat. No. 3,370,411. An example of a bobbin gripper of a type suitable for use in the present invention is described in US. Pat. No. 3,367,098. It is to be understood, however, that numerous other embodiments of bobbin changing apparatuses and bobbin grippers are known.

The power requirements of the driving means for bobbin gripper installations are, in general, quite high. If one of the bobbins held by a bobbin gripper meets, for any reason, an obstacle in its predetermined path of motion, serious damage to the bobbin being transported or to machine parts or the like may result. In rare instances during the installation of empty bobbins on spindles of a spinning or twisting machine, the pivotably mounted spindle shaft can be loaded axially downwardly by forces of high magnitude. For example, in the case that, by accident, an empty spool having an inside diameter which is too small is held on a bobbin gripper, or in the case that residual threads failed to have been removed and are present on the rotatable part of the spindle, the bobbin cannot readily arrive in its predetermined location on the spindle. In other cases, during its downward motion, it exerts a large axial force on the spindle. In unfavorable circumstances this can lead to serious damage to the spindle bearing. Other cases are conceivable in which the bobbin can be unexpectedly impeded in its predetermined path of motion. If, for example, a bobbin held by a bobbin gripper positions itself obliquely with respect to the longitudinal axis of the bobbin gripper, for example, because the thread of its thread winding body had not been torn off in time from the doffing region of the thread in the vicinity of a doffing station of the spindle, then such an obliquely positioned bobbin can bump into machine parts during the further motion of the carrier under unfavorable circumstances. Thus. the incorrectly, obliquely positioned bobbin could be damaged and/or the bobbin gripper and/or the particular machine part could be damaged.

SUMMARY OF THE INVENTION The principal object of the present invention is to provide a bobbin changing apparatus which averts damages to bobbins, machine parts and the like during the bobbin changing operation better than in known automatic bobbin changing apparatuses.

It is a characteristic of the present invention that a safety device is provided, which safety device includes a sensor of sensors. The sensor responds whenever the predetermined motion of at least one of the bobbins carried by a bobbin gripper is impeded during the change of position of the gripper. A safety routine is initiated in response to an output from the sensor indicating that the motion of the bobbin had been impeded.

The safety routine which can be initiated by the safety device can be of any suitable kind effected by relatively simple means. Preferably, the safety device includes switching means which respond to an output signal from at least one of the sensors and arrests the motion of the bobbin gripper associated with that particular sensor or reverses its direction of motion.

The safety device can be provided with optical and- /or acoustical signaling instrumentalities which indicate each reaction of the sensor or sensors optically or acoustically.

Each bobbin gripper is preferably operatively associated with its own sensor which can initiate the safety routine, independently of the condition of the other sensors assigned to the other bobbin grippers, if the bobbin held by the particular gripper is impeded in its predetermined motion by the change of position of the carrier.

In many cases, preferably in case a carrier is provided with only one bobbin gripper or a small number of bobbin grippers, only a single sensor need be provided. The sensor, in this case, is assigned to and operatively associated with the carrier itself or to the driving mechanism of the gripper mechanism. The sensor thus responds whenever the motion of the carrier, i.e. motion of a bobbin held on the carrier by a bobbin gripper, encounters an unexpected resistance to its predetermined desired motion. If, for example, the motion of the carrier is effected by means of a hydraulic or pneumatic cylinder, then the sensor can be a pressure transducer which senses the working pressure of the fluid. In these cases, whenever the pressure rises anomalously, due to the resistance to motion caused by the collision of a bobbin, it initiates the safety routine.

The technique provided by the present invention makes it possible to avert, better than before, the danger of damages to bobbins, machine parts and the like.

As a result of the present invention any danger of damage can even be practically completely avoided if the safety device is embodied in such a way that whenever a sensor responds, further motion of the gripper or carrier, as the case may be, stops or its direction of motion is reversed. This is achieved, for example, by influencing the control or the driving means, for example, by activating a switch which changes the direction of rotation of an electric motor, serving as the driver for the gripper or by switching off the electric motor. If other driving means are used, it is to be understood that the appropriate measures can also be provided.

Each initiation of the safety routine can suitably. additionally, be indicated optically or acoustically so that service personnel are alerted to the disturbance and can relieve it without delay.

In a preferred further embodiment, the bobbin gripper is elastically mounted on the carrier. If, in that case, the bobbin carried by the carrier meets an unforeseen resistance or obstruction, the carrier is displaced relative to the particular bobbin gripper during its further motion. This relative displacement can be sensed by the sensor, preferably an electrical means, such as switches, electrical contacts or the like, and the safety routine can be thus initiated. It is particularly advantageous to choose the elastic mobility of the bobbin gripper or its mounting so that the gripper moves, relative to its associated carrier, both during axial loads on the bobbin carried by it, as well as during pivotal motions of this bobbin. The sensor can be advantageously designed so that the safety routine is effectively initiated by both kinds of undesirable displacements.

It can also be provided, either by itself or in combination with one of the previously mentioned techniques concerning undesirable displacements, that the bobbin held by one of the bobbin grippers can be displaced, relative to its carrier, whenever it encounters a resistance or obstruction impeding its axial motion. For example, axial motion of the bobbin may be impeded because its inside diameter is too small for mounting it on a spindle and the bobbin gripper is operatively associated with a sensor which senses an axial change of position of the bobbin on the bobbin gripper, thus initiating the safety routine.

As already mentioned, the sensor of the safety device can preferably be an electrical sensing means; however, the sensor or sensors can have any suitable construction whatever. For example, the sensors can be electromagnetic, electrohydraulic, electrooptical in nature. Other types of sensors could be used equally well.

The carrier, as mentioned earlier, may carry a large number of bobbin grippers and when suitable, each bobbin gripper has assigned to it its own sensor, then for reasons of cost alone, the sensors can be advantageously developed as electrical contacts or switches of one or several electrical circuits. In order to achieve a particularly inexpensive development of the sensor, the gripper is electrically insulated from the carrier, and electrical contact surfaces are provided on the gripper and on the carrier as the sensor which, when they come in contact with one another, closes an electrical circuit.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial cross-sectional view through a bobbin gripper and carrier of a bobbin changing apparatus: not shown in further detail, to which a safety device ac cording to the present invention is operatively associ ated.

FIG. 2 is a detailed schematic circuit diagram of a driving and safety device of the bobbin changing apparatus of FIG. 1 for the case in which a multitude of bobbin grippers whose assigned sensors can initiate the safety routine independently of one another.

FIG. 3 is a partial cross-sectional view through a modif ed embodiment of the apparatus of FIG. 1.

FIG. 4 is a top view of an electrical contact member of the apparatus according to FIG. 3.

FIG. 5 is a partial cross-sectional view through a third exemplary embodiment of an apparatus according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS For simplification, in the drawings corresponding parts in the various embodiments are provided with corresponding numerals.

The bobbin changing apparatuses 10, 11 and 12 shown respectively in FIGs. 1, 3 and 5, each includes identically developed bobbin gripper carriers 13. On each carrier 13, vertical to the plane of the respective illustrations, a multitude of bobbin grippers 14 is disposed. The grippers 14 are disposed in a row, next to one another, only one bobbin gripper being visible in each of the FIGS. 1, 3 and 5. The bobbin grippers 14, as shown, are developed at their free end in a cone shape, and are provided with a bag-shaped elastic bellows 15 which has its lower end in contact with the cone-shaped portion. The bellows 15 is inflatable by means of fluid under pressure which can be admitted into it through a main channel 16 disposed in the carrier 13 and through a cross channel 17 branching off from main channel 16 and in fluid communication with the interior of the bellows 15. The bellows 15 of all the bobbin grippers 14 of the bobbin changing apparatus are connected to the main channel 16 by cross channels corresponding to the cross channel 17 and are, therefore, simultaneously inflatable. The bellows 15 are inflated whenever they have previously been inserted from above into the interior space of the bobbin 19, shown in phantom lines, so as to grip the bobbins. Because of the inflation and enlargement, the bellows 15 presses against the inner wall of the bobbin 19 to be gripped and holds it in this manner. A more detailed construction of the illustrated bobbin gripper 14 is described in the U.S. Pat. No. 3,367,098.

It is to be understood that, instead of the illustrated bobbin grippers 14, other grippers of a different construction can be used equally well. In the case shown in FIG. 5, the gripper 14 is always to be designed so that it can be inserted from above into the interior of the bobbin 19 and that the bobbin can be displaced axially upwardly during the influence of excessively large axial forces. In the case of the embodiments shown in FIGS. 1 and 3, however, the bobbin grippers 14 can, for example, also be designed so that they extend over the upper end of the bobbin. If the locations of the sensors are changed, the bobbin grippers 14 can be pincershaped and can grasp a bobbin, for example, in the vicinity of its lower end. It is to be understood that other embodiments of bobbin grippers can be used equally well in apparatuses for changing bobbins in accordance with the present invention.

In the exemplary embodiment illustrated in FIG. 1, each bobbin gripper 14 on carrier 13 is provided with one inverted cup-like-shaped first contact member 20. The first contact member 20 has the form of a hollow, circular cylinder, and has a central threaded stud 21 which is screwed into the carrier 13. The bottom of the interior volume 22 of this first contact member 20 carries a deformable elastic spacer 23 in the shape of a circular cylinder made of rubber or synthetic material. The elastic spacer 23 is mounted, for example, by gluing or a similar technique. The outside diameter of the elastic spacer 23 is considerably smaller than the inside diameter of the cylindrical interior volume 22. The elastic spacer 23 extends downwardly somewhat beyond the first contact member 20, and the lower flat surface of this spacer 23 carries a second contact member 24 in the form of a metallic plate, which is fastened by gluing or a similar technique, and into which is screwed a threaded stud 25, which forms part of a metallic holder 26 having the shape of a circular cylinder. The elastic bellows is fastened to the metallic holder 26. The elastic spacer 23 is made of an electrically insulating material so that the second contact member 24, which is normally located at a distance of, for example, l-3 mm below the first contact member 20, is insulated electrically with respect to the first contact member 20.

In a direction perpendicular to the plane of the illustration of FIG. 1, i.e. in the longitudinal direction of the carrier 13, an electrical conductive bar 28 extends along the carrier 13, and is insulated electrically from the carrier 13 by insulation 27. On the bar 28, a further electrical conductor 29 is soldered, whose other end is soldered to the second contact member 24. Corresponding conductors 29 are connected from the bar 28 to other second contact members 24, which are not visible, these other second contact members being respectively associated with respective other bobbin grippers, not visible in FIG. 1. The visible second contact member 24 is thus disposed in an electrical circuit 30 (FIGS. 1, 2), which is supplied by a power supply 31. One terminal of the power supply 31 and the carrier 13 is grounded. The other terminal of the power supply 31 is conductively connected to the bar 28 via an electrical relay 32 and a pilot lamp 33, which is connected in parallel with the relay 32. The function and purpose of the relay 32 is to initiate the safety routine whenever the second contact member 24 comes into contact with the first contact member 20. The safety routine, in the case of the detailed circuit shown in FIG. 2, consists of the arrest of an electric drive motor 34, this drive motor being the one which drives or controls the mechanism, not shown in further detail, which effects programmed changes of position of the carrier 13. The stopping of the motor 34 is achieved by the action of the relay 32, which opens normally closed switch 35 in the electrical supply circuit for the motor 34, each time it is activated, as is diagrammatically illustrated by the dotted lines in FIG. 2. The remaining electrical circuitry of the motor 34 is shown in FIG. 2 as a block 36.

The two contact members and 24, together form the sensor assigned to the bobbin gripper 14 visible in FIG. 1 and act as one of the electrical switches 37, shown in FIG. 2.

If a multitude of bobbin grippers 14 is disposed on the carrier 13, then a separate one of the switches 37, consisting of further first and a further second contact member 20 and 24, is associated with each additional bobbin gripper 14, these separate switches 37 being disposed in parallel to one another in separate circuit branches of the circuit (FIG. 2). These switches 37 are shown schematically in FIG. 2 by the conventional switch symbols for the purpose of simplicity and clarity,

even though they have the unusual construction shown in FIG. 1. The safety device of the gripper changing apparatus includes one or more of the switches 37, the remainder of the circuit 30 and the switch 35. The operation of the safety device is as follows:

Whenever the bobbin 19, shown in phantom lines in FIG. 1 and carried by the bobbin gripper 14, encounters an obstacle during the controlled motion of the carrier 13, either when such an obstacle exerts as axial force in the direction of arrow A upwardly, or when the bobbin 19 is displaced transversely to its longitudinal direction, for example, in the direction of arrow B or C, to the extent that the bobbin gripper 14, because of its elastic mounting to the elastic spacer 23, is displaced so far relative to the carrier [3 that the second contact member 24 abuts the first contact member 20, then this switch 37, constituted by the contact members 20, 24, is closed and the relay 32 is activated, which arrests the driving motor 34 by opening the switch 35. This safety routine is also indicated optically to the service personnel by pilot lamp 33. It is to be appreciated, however, that the circuit element 33 could be an acoustical transducer which would sound an audible alarm or that such a transducer could be provided in addition to the pilot lamp 33.

In the exemplary embodiment of the bobbin changing apparatus shown in FIG. 3, the elastic mounting for the bobbin gripper 14 is effected by an elastic spacer 23, a switch 37' is formed by an inverted cup-shaped first contact member 20 and a disc-shaped second contact member 24' acting as a sensor of the safety device, and its electric circuit 30 all conform in substance and function to corresponding parts used in the embodiment of FIGS. 1 and 2. The circuit 30, shown in FIG. 3, differs from the circuit 30, shown in FIG. 1, in that no pilot lamp is provided and the second contact member 24 disposed on the bobbin gripper 14 is developed, as shown in FIG. 4, as a resilient disc having radial elastic segments 39. The segments 39 are formed by narrow radial slots 40 in the disc. The second contact member 24' is fastened between a shoulder 41, connected rigidly to the gripper 14, which shoulder is integral with a threaded stud 42, on the one hand, and washer-like member or tensioning disc 43, screwed onto the threaded stud 42, on the other hand. The flat lower surface of elastic spacer 23 is fastened to the tensioning disc 43 by means of glue or the like. On the upper end of elastic spacer 23, also by means of glue or the like, an annular disc 44 is fastened. The disc 44, in turn, is fastened to the interior bottom of the inverted cup-shaped first contact member 20 by means of soldering, welding or the like. The cross channel 17 leading to the interior of the bellows 15 of the bobbin gripper 14, serving as the passageway for fluid under pressure, is formed partially, as in FIG. 1, by a central bore through the elastic spacer 23.

A rigid holder 26, carrying the bellows 15 of the bobbin gripper 14, has an external diameter which is somewhat smaller than the inside diameter of the bobbin 19.

The initiation of the safety routine, according to the embodiment of FIG. 3, can occur in a number of ways. Firstly, the safety routine can proceed as a result of deformation of elastic spacer 23, as described in connection with FIG. 1. Secondly, the safety routine can also be initiated, however, in the exemplary embodiment of FIG. 3, directly by the bobbin 19, if the frictional contact of the bobbin 19 of the bellows 15 is overcome by an axial pressure acting on the bobbin 19 before the second contact member 24' comes in contact with the first contact member 20, and where, in that case, the bobbin 19 is displaced on the bobbin gripper 14 axially upwardly until its upper end contacts and bends the elastic segments 39 of the second contact member 24' to such an extent upwardly that at least one of these segments comes in contact with the first contact member 20.

In the exemplary embodiment of the bobbin changing apparatus shown in FIG. 5, the holder 26 of the bellows is fixedly connected to the carrier 13 by a fixed connecting member 45 which has a threaded, axially bored stud extending into the carrier 13. The diameter of the holder 26 is also smaller than the inside diameter of the bobbin 19. For the purpose of initiating the safety routine an electrical circuit 30, which can correspond to circuit 30 of FIG. 1 is provided. An axially movable metallic contact disc serves as a second contact member 24" carried by the fixed connecting member 45. The second contact member 24" is pressed against the flat upper side of the holder 26 by means of a helical, resilient spring 46. It is to be understood that other types of springs and the like can be provided in place of spring 46; for example, a disc spring, a resilient elastic spacer or the like may be substituted for the spring 46.

Spaced above the second contact member 24", there is disposed on the carrier 13 as a first contact member, a contact rail or bar 47 extending in the longitudinal direction of the carrier 13, Le. perpendicular to the plane of FIG. 5. The rail or bar 47 is operatively associated with all of the bobbin grippers 14 carried by the carrier 13. The contact rail or bar 47 is electrically insulated from the carrier 13 by means of insulation 49 and is connected to one terminal of the power supply 31 via a pilot lamp 33 and a relay 32 connected in parallel to the pilot lamp 33. The relay 32 initiates the safety routine as a consequence of its activation. It is to be appreciated that the circuit element 33 could be an acoustical transducer, which could provide an audible alarm signal. If desired, both the pilot lamp and the audible alarm producing transducer could be incorporated in the circuit 30.

Whenever, during downward motion of the carrier 13, the bobbin l9 encounters an obstacle which impedes its further axial downward motion, then the bobbin gripper l4 always travels further downwardly, overcoming the frictional force existing between its bellows 15 and the inner wall of the bobbin 19, until such time as the second contact member 24" touches the top of the bobbin l9, and during the further downward motion of carrier 13, there is established a contact between the contact rail or bar 47 and the second contact member 24". As a consequence, relay 32 is activated, initiating the safety routine. Contacts of the relay 32 either arrest the driving motor which moves the gripper 14 or it reverses its drive mechanism.

The contact rail or bar 47 has the advantage of constructional simplicity, particularly when a large number of gripper devices is provided on the carrier 13. How ever, it is, of course, possible to provide elecrica; switches or the like of different constructions in place of the contact rail or bar 47, these switches being activated by discs 24" which, in that case, do not act as electrical contact members.

In the other possible embodiments, other types of sensors can also be provided instead of those sensors described above, but the described first and second contact members have the advantage, among other advantages, of constructional simplicity. Such contact members are inexpensive to manufacture.

While specific embodiments of bobbin changing apparatuses have been illustrated and described, it is to be understood that various modifications and changes can be made without departing from the essence and scope of the present invention, the scope being defined in the appended claims.

That which is claimed is:

1. An automatic bobbin changing apparatus for a textile machine, the apparatus being particularly useful in conjunction with spinning machines, twisting machines, winding machines and the like comprising, in combination:

a. at least one bobbin gripper for gripping and holding a bobbin;

b. at least one carrier on which said bobbin gripper is disposed;

c. controllable means for effecting movement of said bobbin gripper;

d. sensing means responsive to the impeding of said bobbin gripper in its predetermined path for developing a control signal, said sensing means including a contact member disposed on said bobbin gripper, which contact member is movable against a biasing force relative to said bobbin gripper; and

e. means responsive to the control signal for controlling said means for effecting movement of said bobbin gripper.

2. An apparatus according to claim 1, wherein said at least one bobbin gripper is a plurality of bobbin grippers, said controllable means effect movement of said plurality of bobbin grippers, said sensing means includes a plurality of sensors responsive respectively to the impeding of respective ones of said bobbin grippers in their respective paths for developing respective control signals, and said means for controlling said means for effecting movement is responsive to any of the control signals.

3. An apparatus according to claim 1, wherein said controllable means for effecting movement of said bobbin gripper is coupled to said means for controlling, is responsive to its output signal and becomes deenergized in response to this output signal.

4. An apparatus according to claim 1, wherein said controllable means for effecting movement of said bobbin gripper is coupled to said means for controlling, is responsive to its output signal and reverses the direction of movement of said bobbin gripper in response to this output signal.

5. An apparatus according to claim 4, wherein said bobbin gripper is mounted on said carrier with limited relative possible mobility with respect to said carrier, and said sensing means is responsive to changes of position of said bobbin gripper relative to said carrier.

6. An apparatus according to claim 5, wherein said bobbin gripper is resiliently mounted to said carrier by deformable elastic means, said elastic means being a pad made of elastomeric material.

'7. An apparatus according to claim 5, wherein said bobbin gripper is resiliently mounted on said carrier by deformable elastic means, said deformable elastic means being an elastic spacer positioned between said carrier and said bobbin gripper.

8. An apparatus according to claim 7, wherein said bobbin gripper includes an inflatable bellows, which can be inserted into the upper end of a bobbin to be gripped, said elastic spacer is coaxial with said bobbin gripper. and said bobbin gripper is disposed at the lower end of said spacer, the upper-end of said spacer being disposed on said carrier.

9. An automatic bobbin changing apparatus for a textile machine, the apparatus being particularly useful in conjunction with spinning machines, twisting machines, winding machines and the like comprising, in combination:

a. at least one bobbin gripper for gripping and holding a bobbin;

b. at least one carrier on which said bobbin gripper is disposed;

c. controllable means for effecting movement of said bobbin gripper;

d. sensing means positioned above and at some distance from any bobbin normally gripped by said bobbin gripper and responsive to the impeding of said bobbin gripper in its predetermined path for developing a control signal, said sensing means being activatable by a bobbin grasped by said bobbin gripper, whenever this bobbin is displaced up to a predetermined position on said bobbin gripper and contacts said sensing means after overcoming the frictional force exerted by said bobbin gripper on the bobbin;

. means responsive to the control signal for controlling said means for effecting movement of said bobbin gripper; and means for fixedly connecting said bobbin gripper to said carrier.

10. An apparatus according to claim 9, including an electrical circuit and spring means, and wherein said sensing means includes a plate mounted at some distance above any bobbin normally gripped by said bobbin gripper, and plate being mounted axially movable against the effect of said spring means, said plate being axially displaceable by a bobbin to effect closing of said electrical circuit.

11. An automatic bobbin changing apparatus for a textile machine, the apparatus being particularly useful in conjunction with spinning machines, twisting machines, winding machines and the like comprising, in combination:

a. at least one bobbin gripper for gripping and holding a bobbin;

b. at least one carrier on which said bobbin gripper is disposed; c..-controllable means for effecting movement of said bobbin gripper;

d. sensing means responsive to the impeding of said bobbin gripper in its predetermined path for developing a control signal; and

. means responsive to the control signal for controlling said means for effecting movement of said bobbin gripper; and wherein said bobbin gripper is electrically insulated with respect to said carrier and said sensing means comprise a pair of electrical contact surfaces formed by members which normally lie separated and opposite one another on said bobbin gripper and on the carrier respectively and said sensing'means includes an electrical circuit which is completed-by said members.

I 12. An automatic bobbin changing apparatus fora textile machine, the apparatus being particularly useful in conjunction with spinning machines, twisting machines. winding machines and the like comprising, in combination;

a. at least o'nebobbin gripper for gripping and holding a bobbin;

b. at least one carrier on which said bobbin gripper is disposed; v

.c. controllable means for effecting movement of said bobbin gripper;

d. sensing means responsive to the impeding of said bobbin gripper in its predetermined path for developing a control signal wherein said sensing means includes:

1. a first ring-shaped electrical contact surface disposed at some distance above any bobbin grasped by said bobbin gripper, said first ringshaped electrical contact surface being approximately coaxial with the axis of said gripper; and

2. a second coaxial ring-shaped electrical contact surface provided on said carrier at a given axial distance from said first electrical contact surface; and

e. means responsive to the control signal for controlling said means for effecting movement of said bobbin gripper.

13. An apparatus according to claim 12, wherein said first electrical contact surface includes a multitude of distinct contact surfaces which are electrically connected with one another and are distributed concentrically around the axis of said bobbin gripper.

14. An apparatus according to claim 12 including an elastic spacer positioned between said carrier and said bobbin gripper, said spacer being a pad of elastomeric material.

15. An apparatus according to claim 12, wherein said controllable means for effecting movement of said bobbin gripper is coupled to said means for controlling, and is responsive to its output signal and reverses the direction of movement of said bobbin gripper in response to this output signal.

16. An apparatus according to claim 12, wherein said at least one bobbin gripper is a plurality of bobbin grippers, said controllable means effect movement of said plurality of bobbin grippers, said sensing means includes a plurality of sensors responsive respectively to the impeding of respective ones of said bobbin grippers in their respective paths for developing respective control signals, and said means for controlling said means for effecting movement is responsive to any of the control signals.

17. An apparatus according to claim 12, wherein said controllable means for effecting movement of said bobbin gripper is coupled to said means for controlling, is responsive to its output signal and becomes deenergized in response to this output signal.

18. An apparatus according to claim 12, wherein said controllable means for effecting movement of said bobbin gripper is coupled to said means for controlling, is responsive to its output signal and reverses the direction of movement of said bobbin gripper in response to this output signal.

19. An apparatus according to claim 18, wherein said bobbin gripper is mounted on said carrier with limited relative possible mobility with respect to said carrier, and said sensing means is responsive to changes of position of said bobbin gripper relative to said carrier.

20. An apparatus according to claim 19, wherein said bobbin gripper is resiliently mounted to said carrier by deformable elastic means, said elastic means being a pad made of elastomeric material.

21. An apparatus according to claim 19. wherein said bobbin gripper is resiliently mounted to said carrier by an elastic spacer positioned between said carrier and said bobbin gripper.

22. An apparatus according to claim 21, wherein said bobbin gripper includes an inflatable bellows, which tached. 

1. An automatic bobbin changing apparatus for a textile machine, the apparatus being particularly useful in conjunction with spinning machines, twisting machines, winding machines and the like comprising, in combination: a. at least one bobbin gripper for gripping and holding a bobbin; b. at least one carrier on which said bobbin gripper is disposed; c. controllable means for effecting movement of said bobbin gripper; d. sensing means responsive to the impeding of said bobbin gripper in its predetermined path for developing a control signal, said sensing means including a contact member disposed on said bobbin gripper, which contact member is movable against a biasing force relative to said bobbin gripper; and e. means responsive to the control signal for controlling said means for effecting movement of said bobbin gripper.
 2. a second coaxial ring-shaped electrical contact surface provided on said carrier at a given axial distance from said first electrical contact surface; and e. means responsive to the control signal for controlling said means for effecting movement of said bobbin gripper.
 2. An apparatus according to claim 1, wherein said at least one bobbin gripper is a plurality of bobbin grippers, said controllable means effect movement of said plurality of bobbin grippers, said sensing means includes a plurality of sensors responsive respectively to the impeding of respective ones of said bobbin grippers in their respective paths for developing respective control signals, and said means for controlling said means for effecting movement is responsive to any of the control signals.
 3. An apparatus according to claim 1, wherein said controllable means for effecting movement of said bobbin gripper is coupled to said means for controlling, is responsive to its output signal and becomes de-energized in response to this output signal.
 4. An apparatus according to claim 1, wherein said controllable means for effecting movement of said bobbin gripper is coupled to said means for Controlling, is responsive to its output signal and reverses the direction of movement of said bobbin gripper in response to this output signal.
 5. An apparatus according to claim 4, wherein said bobbin gripper is mounted on said carrier with limited relative possible mobility with respect to said carrier, and said sensing means is responsive to changes of position of said bobbin gripper relative to said carrier.
 6. An apparatus according to claim 5, wherein said bobbin gripper is resiliently mounted to said carrier by deformable elastic means, said elastic means being a pad made of elastomeric material.
 7. An apparatus according to claim 5, wherein said bobbin gripper is resiliently mounted on said carrier by deformable elastic means, said deformable elastic means being an elastic spacer positioned between said carrier and said bobbin gripper.
 8. An apparatus according to claim 7, wherein said bobbin gripper includes an inflatable bellows, which can be inserted into the upper end of a bobbin to be gripped, said elastic spacer is coaxial with said bobbin gripper, and said bobbin gripper is disposed at the lower end of said spacer, the upper end of said spacer being disposed on said carrier.
 9. An automatic bobbin changing apparatus for a textile machine, the apparatus being particularly useful in conjunction with spinning machines, twisting machines, winding machines and the like comprising, in combination: a. at least one bobbin gripper for gripping and holding a bobbin; b. at least one carrier on which said bobbin gripper is disposed; c. controllable means for effecting movement of said bobbin gripper; d. sensing means positioned above and at some distance from any bobbin normally gripped by said bobbin gripper and responsive to the impeding of said bobbin gripper in its predetermined path for developing a control signal, said sensing means being activatable by a bobbin grasped by said bobbin gripper, whenever this bobbin is displaced up to a predetermined position on said bobbin gripper and contacts said sensing means after overcoming the frictional force exerted by said bobbin gripper on the bobbin; e. means responsive to the control signal for controlling said means for effecting movement of said bobbin gripper; and f. means for fixedly connecting said bobbin gripper to said carrier.
 10. An apparatus according to claim 9, including an electrical circuit and spring means, and wherein said sensing means includes a plate mounted at some distance above any bobbin normally gripped by said bobbin gripper, and plate being mounted axially movable against the effect of said spring means, said plate being axially displaceable by a bobbin to effect closing of said electrical circuit.
 11. An automatic bobbin changing apparatus for a textile machine, the apparatus being particularly useful in conjunction with spinning machines, twisting machines, winding machines and the like comprising, in combination: a. at least one bobbin gripper for gripping and holding a bobbin; b. at least one carrier on which said bobbin gripper is disposed; c. controllable means for effecting movement of said bobbin gripper; d. sensing means responsive to the impeding of said bobbin gripper in its predetermined path for developing a control signal; and e. means responsive to the control signal for controlling said means for effecting movement of said bobbin gripper; and wherein said bobbin gripper is electrically insulated with respect to said carrier and said sensing means comprise a pair of electrical contact surfaces formed by members which normally lie separated and opposite one another on said bobbin gripper and on the carrier respectively and said sensing means includes an electrical circuit which is completed by said members.
 12. An automatic bobbin changing apparatus for a textile machine, the apparatus being particularly useful in conjunction with spinning machines, twisting machines, winding machines and tHe like comprising, in combination: a. at least one bobbin gripper for gripping and holding a bobbin; b. at least one carrier on which said bobbin gripper is disposed; c. controllable means for effecting movement of said bobbin gripper; d. sensing means responsive to the impeding of said bobbin gripper in its predetermined path for developing a control signal wherein said sensing means includes:
 13. An apparatus according to claim 12, wherein said first electrical contact surface includes a multitude of distinct contact surfaces which are electrically connected with one another and are distributed concentrically around the axis of said bobbin gripper.
 14. An apparatus according to claim 12 including an elastic spacer positioned between said carrier and said bobbin gripper, said spacer being a pad of elastomeric material.
 15. An apparatus according to claim 12, wherein said controllable means for effecting movement of said bobbin gripper is coupled to said means for controlling, and is responsive to its output signal and reverses the direction of movement of said bobbin gripper in response to this output signal.
 16. An apparatus according to claim 12, wherein said at least one bobbin gripper is a plurality of bobbin grippers, said controllable means effect movement of said plurality of bobbin grippers, said sensing means includes a plurality of sensors responsive respectively to the impeding of respective ones of said bobbin grippers in their respective paths for developing respective control signals, and said means for controlling said means for effecting movement is responsive to any of the control signals.
 17. An apparatus according to claim 12, wherein said controllable means for effecting movement of said bobbin gripper is coupled to said means for controlling, is responsive to its output signal and becomes de-energized in response to this output signal.
 18. An apparatus according to claim 12, wherein said controllable means for effecting movement of said bobbin gripper is coupled to said means for controlling, is responsive to its output signal and reverses the direction of movement of said bobbin gripper in response to this output signal.
 19. An apparatus according to claim 18, wherein said bobbin gripper is mounted on said carrier with limited relative possible mobility with respect to said carrier, and said sensing means is responsive to changes of position of said bobbin gripper relative to said carrier.
 20. An apparatus according to claim 19, wherein said bobbin gripper is resiliently mounted to said carrier by deformable elastic means, said elastic means being a pad made of elastomeric material.
 21. An apparatus according to claim 19, wherein said bobbin gripper is resiliently mounted to said carrier by an elastic spacer positioned between said carrier and said bobbin gripper.
 22. An apparatus according to claim 21, wherein said bobbin gripper includes an inflatable bellows, which can be inserted into the upper end of a bobbin to be gripped, said elastic spacer is coaxial with said bobbin gripper, and said bobbin gripper is disposed at the lower end of said spacer, the upper end of said spacer being disposed on said bobbin carrier.
 23. An apparatus according to claim 21, wherein said elastic spacer is a pad of elastomeric material.
 24. An apparatus according to claim 23, wherein one of said contact surfaces is a face of a dome-shaped member to which said pad of elastic material is attaChed. 